Differential gear



Apfil 1 1924. l 1,488,581

A l. C. WOODWARD y DIFFERENTIAL GER Filed Feb.. 2l, 1923 2 Sheets-Sheet 1 121, k .1i l.9.1 1;:-

l Patented pr. 1, 1924, l l

uNlrEDisrArE- s l1,488,581 lui'rii-iar oFFicE.

A:ti'tviisre o. WooDwAnip, or' sYRACUsE, NEW Yonx,

' DI'rrEnEN'rrAL GEAR.

l Applica-tion l'ed February tial'Gears, of which the following is a speci'- fication.

^ This' invention relates to differential gear ofthe type employed in vehicle drive mecha- 'nisms An object of the inv ntionis to improve suclr'gearing so tha't it is controllable to offer any desired graduated resistence to differential action according to the power of-a vehicle andthe load which itis intended to carry, and the effortto differentiate between the drivenA wheels. It is also an object of the invention toprovide convenient-means for i .20

rendering the said control mechanism inoperative, if desired. so that under 'good road conditions, the differential/gearing is made free for differentiating with the minimum 0f. inherent "resistence Prior .to this invention,means have been provided for positively preventing at de- 'sired times any differential motionbetween the elements of the differential gearing, and it is also well-known 'in the art toprovide frictional resistence `in the differential gearing tov at all times prevent free-'differential action, or a tendency of one wheel to race 1f it does not have good traction or rises clear of the road surface. #The first of these two rior types of controllin devices is usually 1n the form of a pair-.of )awed clutches, one

of which is splinedto one of the axles, so as i -to be in driving relation therewith .and slidable along the axle to engage the coacting clutch member, which is generally formed in the pinion support or casing of the differential gearing. Such construction,- therefore, either -positively prevents-differential action,l

or when thrown out, has no restraining effect whatever. The second formofprior device mentioned is usually in the form of i friction disks which may be similarly placed wheels.

as the jaw clutch type, but are always in ac' tion, and, therefore, offer'a fixed resistence which is overcome by some predetermined effort to differentiate between the driven The present invention relates to the abovementioned friction type of restraining means for differential gears, ybut is improved so that the frictional resistence may be easily 21, 19%. Serial No. 620,335.

varied to suit different cars, and the mechanism is made controllable so as to readily vbe placed intol or outl of action the same as-the first-mentioned type' of jaw clutch device.

An illustrative embodiment of this invem tionissliown in the accompanying drawings, wherein Figure -1 is a sectional plan view of a differential 'gearing 'including a clutch mechanism constructed according to this invention. Y 4

Figure v2 is an enlarged central longitudinal section'of the clutch mechanism, part of the differential mechanism being shown in elevation.

a Figure 3 is a transverse 'section taken on the line 3 3 of Figure 2.

Figure the line 4 4 of Figure 2.'

Figures 5 and 6 are transverse sections.

taken lrespectively on. the lines 5 5 and 6 6 of Figure 2. Figure 7 is an end view of the sleeve which connects the jaw clutch with the. friction clutch. A

Figure 8 is a section takenl on the line 8 8 of Figure 7.

It is well-known in this art that vehicle differential gearing which is not/,provided with: means Vfor restraining itsv differential action' is highlyl efficient under circumstances where'the wheels have good traction `on a level road, but that under certain circumstances the action -of such gearingis dan- 4 is a transverse sectionl taken on gerous in that it has a tendency to cause one wheel torace if the road is slippery and the brakes are unevenly applied. This results in a turning torque and 'side vslipping of the vehicle. The unrestrained differential gearing also has a bad effect on the mechanism of the car as a whole during fast driving over a rough "road, in that when one wheel loses traction by rising more or less from the road surface it speeds up and is then suddenly checked, when it again attains ood traction. This has a racking effect on t e car which 'shortens its life., Axles are also frequently broken through the operation .of an unrestrained differential gear attimes, which results in the entire work of driving the car bein effected by one wheel alone.

With the present construction,l the fricl ings.

it effective or ineffective at the-will of the driver of the car. y

ln the form shown, the ditferentialgearing is arranged within the usual frame structure or housing 1. Power shaft. 2, and driven shafts -3 and 4 havev their ends supported in the housing 1 by the usual bearwhich meshes with a gear 6"'secured to a planetary gear housing S havlng a hub 9.1

, supported in a bearing 7 of the housing 1 and a hub 9, whichis in tur-n journaled concentrically with the shaft 4 in. a ball bearing 10 of the housing 1. A. plurality of planetary gears 11 arejournaled on stud shafts carried by the housing 8, and. mesh with beve-led .gears 12 and 13 fixed on the shafts 3 and 4, respectively.

The present invention resides in the means for controlling the action of the differential gearing, and in the particular form illustrated comprises a clutch mechanism interposed between the planetary gear housing 8 and the shaft 4, it Ybeing understoodl that the locking of the shaft 4 to the housing 8,

. has thefeffect of locking the entire differential gearing, thereby compelling both shafts 3v and 4 to rotate as'a' unit.

iev

' 4, so as to be movable axially into and out` The clutchl mechanism includes a jaw clutch and a disk friction clutch arranged so that the friction clutch will yield to permit a relative movement of the driven mem'- bers, thereby producing differential action, when the jaw clutch is 'subjected to a predetermined loa-d.

The clutch -mechanism comprises a jaw 4clutch 14'and a multiple disk friction clutch 15, coaxially arranged on the driven shaft 4.

The jaw clutch 14 comprises a pair of elements 16' and l17 having interfitting shoulders 18`on their opposed faces. In the par-- ticular construction shown, the clutch element 16 is formed integral with the hub 9 of the planetary gear housing 8. The clutch `element 17 is loosely mounted on the shaft of driving relation with the clutch element 16. Formed on the periphery of the element 17, is an annular groove V19 to receivean operating arm or lever 20. Splined to the periphery of the clutch element 17 and pro- ]ectingbeyond one end thereof, is a sleeve 21 which 1s arranged to form a housing for ther friction clutch 15. The sleeve 21 and the friction clutch 15 form the, connection between the jaw clutch 14 and the driven shaft 4.

As illustrated, the friction clutch 15, comprises a. plurality of alternately arranged disks 22 and 23. The disks 22 are loose on the shaft 4 and are splined to the inner wall of the sleeve 21, whiie the disks' 23 are loose in the sleeve 21 and are splined to the shaft 4. Loosely mounted between the end disk 22 and shoulders 24 formed on the splines The driving shaft 2 has a pinion 5,-'

Maasai of the sleeve 21, is an vannular bearing member 25 which limits the inward Ymovement of the clutch. element 17 and also serves to take up the thrust 'of the friction disks 22 and 23 under the action of a clamping mem ber 261 The' clamping member 26 is in the form of a gland and is threaded to the sleeve 21 so as to be axially adjustable for varying the friction between the disks 22 and 23.

VVhen the clutch velements16 and 17 are engaged, the friction clutch 15 holds the housing 8 in driving relation with the shaft 4, whereby both of the driven shafts 3 and 4 will be rotated in unison under normal conditions. The operating arm 2() mav be actuated and locked, so as to hold the cliitch member 17 open, by any of the usual forms fof `lever and toggle mechanisms.

The operation of the device shown is as ,followszy When the clutch 14 is open, the power is transmitted as usual so that the driven shafts-will each receive an -equal amount of power when the tractiv'e resistence of the vehicle lwheels is equal. `When the vehicle is driven in a curve, the wheel traversing the path of lesser radius slows down accordingly, while the wheel traversing the path of grea-terradius increases its speed as usual, but the power is properly divided between the wheels. f

When, however, the pavement is'slippery or the vehicle is on a steep grade or when the road is rou h so that the vehicle wheels are sometimes ifted clear of the road, the

operator may prevent skidding, racing of the engme, loss of traction and other troubles inherent in the usual differential gearing by throwing inthe gear locking aw clutch. lf, due to'vroad conditions or the manner of operating the vehicle, one of the driven wheels loses its trat-tional .hold on the road, the clutch mechanism will insure an amount of-power up to the limit of the holding power of the friction clutch, to be positively delivered to both driven shafts, but, if the circumstances are such that-the strain'on the Aclutch mechanism is suicientto overcome the holding power of the friction clutch, then the disks 22 and 23 will yield to permit a relative rotation ofhaving coacting parts adapted to be placed into-and out of driving relation to eachI other, anda friction clement interposed between said clutch and one of said two members, said friction element being arranged to permit a relative movement of said two members when the load on said clutch ex-. ceeds a predetermined amount. .l

3. In a differential gear mechanism including a driving member and la pair of driven members, the combination of a clutch interposed between two of said members) said clutch comprising a pair of elements having coactingparts adapted to be placed into and out of driving relation to each other, one of said clutch elements being loosely mounted onv one of said two members," and a friction element ,interposed bctween said one member and said one clutch element for normally holding them in driving relation to each other, said friction element being arranged to permit a relative movement of said two members when the load on said clutch exceeds a predetermined amount.

4. In a differential gear mechanismincluding a driving member and a pair of driven members, the combination of a clutch interposed between two of said-members, said clutch. comprising a pair of coacting elements, one of said elements bein loosely mounted on'one of said two mem ers and being movable into and out of driving relation with the 'other of said clutch elements, and a friction element interposed between said one memberand said one clutch element for normally holding them in driving relation to each other, said friction element being arranged totpermit a relative movement of said two members when the load on said clutch exceeds a predetermined amount.

5. In a differential gear mechanism including a ,drivin member and a pair of driven members, t e combination of a clutch interposed betweenv two of said members, said clutch comprising a pair of .K elements having coacting parts adapted to be placedv into and out of driving relation to each other, and a pair ofcoacting friction velements arranged to normally hold one of said clutch elements in driving relation to one of saiditwo members, one of said friction elements being fixed to rotate with said one clutch element, the other .of said friction elements being fixed to rotate with said one member, said friction elements being adapted to yield to permit a relative movement of said two members-when the load on said clutch exceeds a predetermined amount.

6. In 4a differential gear mechanism4 including a driving member and a pair of driven members, the combination of a clutch interposed between two of said members, said clutch comprising a pair of elements into and out of driving relation to each other, a air of coacting friction elements intel-pose between one of said clutch elements and one of said two members for normally holding them in driving relation to each other, said friction elements being adapted to yield to permit a relative movement of Isaid two members when the load on said clutch exceeds a predetermined-amount, and means for varying the pressure between said friction elements.

7. In a differentialfgear mechanism including a driving member and a pair of driven members, the combination of a clutch interposed between two of said members, said clutch comprising a pairof elements having coacting parts adapted to be placed into and outof driving relation to each other, a pair of friction 'discs concentrically arranged on one of said two members, one of said disks being fixed to rotate with one of said clutch elements, the other of said disks being fixed to rotate with said lone member, said disks coacting with each other to normally hold said one member in driving relation to said one clutch element and being adapted to yield to permit a relative movement of said4 two members when the load on said clutch exceeds a, predetermined amount, and means for adjusting one of said disks axially with-respect to the other -disk for varying the friction between the opposed faces of said disks.

8. In ay differential gear mechanism including a drivingr member `and a pair of driven members, the combination of a' clutch interposed between two of said members, said clutch comprising a pair of coacting elements, one of said elements being loosely mounted on one of said two members and being movable into and out of driving relation with the other of said clutch elements, a sleeve splined on said one clutch element, and a friction element interposed between Said sleeve and saidone member for nor- .mally holding them in driving relation to each other, said friction element being arranged to permit a relative movement of said two members when the load on said clutch exceeds a predetermined amount.

9. In a differential gear mechanism inhaving coacting parts adapted to be placedv cluding a driving member and a pair of driven members, thel combination of a, clutch interposed between two of said members,

said clutch comprising` a pairof coacting elements, one of said element-s being `loosely mounted on one of said two members. and being movable into and out of driving relation with the other of said clutch elements, a sleeve splined on said one clutch element, and a. pair of friction disks concentrically arranged on said one member, one of said disks bein,g T splined to'said one member, the other of said disks beine splined to said sleeve, said disks coaeting with each other to normally hold said one member .in driving relation to said one clutch element and being adapted to yield to permit a relative movement of said two members when the load on said clutch exceeds a. predetermined amount.

10. In a differential gear mechanism inclnding a driving` member and a pair of driven members, thecombination of a, clutch interposed between two of said members, said clutch comprising a pair of coacting elements, one of said element-s being loosely mounted on one of said two members and being movable into and out of driving relation with the other of said clutch elements, a sleeve splined on said one clutch element, a pair of friction disks concentrically arranged on saidone member, one of said disks being splined to said one member, the other of said disks being,r splined to said sleeve, said disks coacting with each other to normally hold said one member in driving relation to said one clutch element and being Lessa Aadapted to yield to permit a relative movement of said two members when the' load on saidclutch exceeds a predetermined amount, and means for axially adjusting one of said disks relative to the other for varying the friction between said disks.

l1. ln a differential gear mechanism'including a driving member and a pair of driven members, the combination of a clutch interposed between two ofsaid members, said clutch comprising a pair of coacting elements, one ofl said elements being loosely mounted on one of said two members and being movable into and out of driving relation with the other of said clutch elements,

a sleeve splined on said one clutch element and projecting beyond one end thereof, a pair Aof friction disks concentrically arranged within the projecting part of said sleeve. one of said disks being splined to said sleeve, the other disk being splined to said one member, said disks coacting with v each other to normally hold said one member in driving relation to said one clutch element and being adapted to iyield to permit a relative movement of said f two members when the load on said clutchexceeds a, prede` thisieai day 

